The present invention relates to a window comparator circuit and, more particularly, a window comparator circuit suitable for integrating.
Various window comparator circuits have been provided to determine whether or not a signal voltage is in a predetermined voltage range. One of these circuits which processes only an input signal whose polarity is not changed includes first and second reference voltage supply terminals of high and low levels whose polarities are the same as that of the input signal, two comparators and a NAND gate. The first reference voltage supply terminal and signal input terminal are connected to noninverting and inverting input terminals of the first comparator, respectively. The signal input terminal and second reference voltage supply terminal are connected to noninverting and inverting input terminals of the second comparator, respectively. Output terminals of the first and second comparators are adapted to be connected to a signal output terminal through the NAND gate. In the case of a circuit thus arranged, an output voltage becomes L level when the input voltage is lower than the second reference voltage or higher than the first reference voltage and H level when the input voltage is higher than the second reference voltage or lower than the first reference voltage.
About sixth elements are required to form this conventional window comparator circuit by means of standard gate circuits, thus making the conventional window comparator circuit unsuitable for integrating.